The present invention relates to a chair assisting rising movements, and more particularly to a chair assisting rising movements provided with a reclining function and a rising function.
Chairs provided with reclining functions are conventionally known in which backseats may be tilted rearward for enabling comfortable postures.
However, it is the case with such conventional chairs provided with reclining functions that persons with weakened leg muscles find it hard to perform sitting actions or rising actions since they need to take stooped postures.
The present invention has been made in view of the above drawback of the prior art, and it is an object thereof to provide a chair assisting rising movements enabling easy sitting and rising actions and being superior in safety and comfort.
It is another object thereof to provide a chair assisting rising movements that is comfortable at the time of performing rising action, sitting action or in reclined condition, on which one may take safe and comfortable posture, whose armrests are easy-to-use, in which wiring from the control circuit box can be shortened, and with which height adjustment may be easily performed to suit short persons and tall persons.
For solving the above subjects, the present invention provides a chair assisting rising movements that is comprised of a reclining block 1 including a seat surface 2a and a backrest 3 that can be tilted in a rearward direction, a mount base block 20 that is placed on a floor surface, and an intermediate base block 15 provided between these blocks, the chair further comprising a first link 4 for connecting the reclining block 1 to a rear end portion 15b of the intermediate base block 15 in a freely rotating manner, a second link 5 for connecting a front portion 20f of the mount base block 20 to a front end portion 15a of the intermediate base block 15 in a freely rotating manner, and a third link 6 for connecting a rear portion 20g of the mount base block 20 to the rear end portion 15b of the intermediate base block 15 in a freely rotating manner, and the chair further comprising a reclining movement mechanism 7 for moving the backrest 3 from a stationary position to a rearward tilted condition through rotation of the first link 4, and a rising movement mechanism 8 for raising the seat surface 2a of the reclining block 1 from a stationary position to a specified height via the intermediate base block 15 through rotation of the second link 5 and the third link 6.
With this arrangement, a comfortable posture can be taken by tilting the backrest 3 of the reclining block 1, and the seat surface may be raised to a suitable height when performing sitting or rising action by moving the intermediate base block 15 upward so that sitting and rising may be easily performed without stooping.
It is further preferable that the second link 5 and the third link 6 are arranged to be of different lengths such that the rear end portion 15b of the intermediate base block 15 becomes higher than its front end portion 15a at the time of rising movement. With this arrangement, the seat surface 2a will be inclined in a front-downward manner when the intermediate base block 15 is pushed upward such that it is inclined in a front-downward manner at the time of rising movement, and a person taking seat may perform sitting and rising actions in a more comfortable manner.
It is further preferable that the chair is of an arrangement in which the load applied to the second link 5 and the third link 6 at the time of rising movement is not reversed during rotation of the links. In other words, by continuously making load apply on the second link 5 (or similarly to the third link 6) in a single direction from above, jerkiness at the time of rising movement can be eliminated.
It is further preferable that the intermediate base block 15 is provided with a receiving member 21 for maintaining the intermediate base block 15 mounted on the mount base block 20 in the stationary position. In this case, by making the receiving member 21 mount on the mount base block 20 when the intermediate base block 15 has returned to its stationary position, occurrence of rattling movement can be prevented at the time of taking a seat or reclining.
It is further preferable that a footrest 12 is connected in a freely rotating manner to a front end side of the seat surface 2a of the reclining block 1, and the chair being provided with a control portion 16 for enabling rising movement only when the footrest 12 and the backrest 3 are in stationary positions. With this arrangement, it is possible to prevent the reclining block 1 from erroneously performing upward movement at the time of performing reclining movement of the backrest 3 or when using the footrest 12.
It is further preferable that in case an operation for rising movement is directed when the backrest 3 and the footrest 12 are not in stationary positions, the control portion 16 performs rising movement only after the backrest 3 and the footrest 12 returned to their stationary positions. With this arrangement, it is possible to eliminate trouble such as operating the rising switch many times.
It is further preferable that the chair is provided with a mechanism of varying an angle of the seat surface 2a at the time of reclining movement of the backrest 3. With this arrangement, the user can comfortably lay down in a natural posture since the angle of the seat surface 2a is varied at the time of reclining movement.
It is further preferable that the chair is arranged in that a central side of the seat surface 2a is supported by the intermediate base block 15 in a freely rotating manner while a rear end portion 2b of the seat surface 2a is suspended from the backrest 3 via a suspending link 9. With this arrangement, the mechanism for varying the angle of the seat surface 2a when the backrest 3 is reclined can be realized in a small-sized and light-weighted manner.
It is further preferable that armrests 11 are fixed to the seat surface 2a such that their angles with respect to the seat surface 2a are maintained to be constant. With this arrangement, the armrests 11 descent together with the declining of the seat surface 2a in linkage with the backrest 3 upon reclining the backrest 3 so that a posture for resting one""s arms will not become unnatural.
It is further preferable that a control circuit box incorporating the control portion 16 therein is mounted to the intermediate base block 15. With this arrangement, wiring from the control circuit box can be shortened even at the time of reclining movement and rising movement.
It is further preferable that the rising movement mechanism 8 is comprised of an electric actuator for raising movement 8a for rotating the second link 5 and the third link 6, the electric actuator for raising movement 8a being disposed to be substantially horizontal to the floor surface 22. With this arrangement, an internal mechanism of the chair assisting rising movements can be low and the seat surface 2a can be maintained at a low level as well.
It is further preferable that the chair is provided with an adaptor 23 for adjusting a height of the seat surface 2a with respect to the floor surface 22. With this arrangement, height adjustment for short and tall persons can be performed by the adaptor 23.
It is further preferable that the chair is provided with a mechanism for decreasing a height of the seat surface 2a to be lower than that of the stationary position when performing reclining movements of the backrest 3. With this arrangement, a comfortable posture can be taken at the time of performing reclining movements.